1. Field of the Invention
The present invention relates to a magnetic head to be mounted in a hard magnetic disk device and the like, and to a production method therefor.
2. Description of the Related Art
In a conventional magnetic head to be mounted in a hard magnetic disk device and the like, as shown in FIGS. 19 and 20, a load beam 60 made of a stainless steel plate is provided with a mounting section 61, a flexible printed circuit board 62, and a flexure 63 made of a stainless steel thin plate. On the surface of the flexure 63, a conductive pattern 63b is formed via a resin layer of polyimide or the like and is electrically connected to a wiring section of the flexible printed circuit board 62.
The leading end of the flexure 63 is partly cut out to form a tongue portion 63a which has a slider S5 fixed thereon.
The slider S5 comprises a nearly rectangular slider substrate 64 made of a ceramic material, such as Al2O3xe2x80x94TiC, a head element 65 formed on one end face 64a of the slider substrate 64, bumps 66 made of a good conductive material, such as Ni, so as to be electrically connected to the head element 65, and a protective film 67 made of an insulating material, such as alumina, so as to cover the head element 65. Exposed portions 66a of the bumps 66 exposed from the protective film 67 are flush with or protrude from the surface of the protective film 67.
The other end face 64d of the slider substrate 64 on the opposite side from the one end face 64a is a planar surface in parallel with the one end face 64a. On an upper surface 64c of the slider substrate 64 orthogonal to the one end face 64a, a silicon film and a carbon film are stacked in order, and an air groove 64e and rail portions 64f on both sides of the air groove 64e are formed, thereby forming a magnetic disk opposing surface of the slider S5.
A bottom surface 64b of the slider substrate 64 of the slider S5 on the opposite side from the upper surface 64c is fixedly bonded to the flexure 64. At the corners formed between the end face 64a of the slider S5 and the flexure 63, nearly spherical balls 69 made of metal, such as Au, are bonded to both the exposed portions 66a of the bumps 66 and the leading end of the conductive pattern 63b, whereby the bumps 66 and the conductive pattern 63b are electrically connected via the balls 69.
A method for producing the slider S5 of the conventional magnetic head will now be described. Referring to FIG. 21, a plurality of head elements 65 and bumps 66 respectively connected thereto are arranged on the surface of a wafer 70 made of a ceramic material, such as Al2O3xe2x80x94TiC, so as to serve as a base material of slider substrates 64. Subsequently, a protective film 67 is formed on the surface of the wafer 70 so as to cover the head elements 65 and the bumps 66, and the surface of the protective film 67 is lapped so as to expose exposed portions 66a of the bumps 66 from the protective film 67.
Then, as shown in FIG. 22, the wafer 70 is cut into slider bars 68 so that the cutting surfaces serve as upper surfaces 64c and bottom surfaces 64b of slider substrates 64. A plurality of head elements 65 and bumps 66 are arranged on one side face 68a of each slider bar 68. The other side face 68d of the slider bar 68 on the opposite side from the one side face 68a is a planar surface in parallel therewith.
As shown in FIG. 23, a plurality of slider bars 68 are placed on a jig 72 so that one side faces 68a are oriented in the same direction and so that bottom surfaces 68b, serving as the bottom surfaces 64b of the slider substrates 64, are fixedly bonded to the jig 72. In this case, as shown in FIG. 24, the exposed portion 66a of the bump 66 in each slider bar 68 is in contact with the other side face 68d of the adjoining slider bar 68.
Subsequently, a silicon film and a carbon film are deposited and stacked in order on upper surfaces 68c of the slider bars 68, serving as the upper surfaces 64c of the slider substrates 64, by ECR-CVD.
A resist film (not shown) is formed on the upper surfaces 68c of the slider bars 68 and is patterned by photolithography so as to conform to the shape of a magnetic disk opposing surface of the slider S5.
In a dry etching process, portions of the upper surfaces 68c of the slider bars 68 exposed from the resist film are removed by irradiation with ions or electrons, thereby forming magnetic disk opposing surfaces of the sliders S5.
Then, the resist film is stripped off the upper surfaces 68c of the slider bars 68, and the slider bars 68 are separated from the jig 72 and each are divided into sliders S5. The production of sliders S5 is thereby completed.
In the conventional magnetic head and the production method therefor described above, the exposed portions 66a of the bumps 66 exposed from the protective film 67 of the slider S5 are in contact with the other end face 64d of the slider substrate 64 made of Al2O3xe2x80x94TiC in another slider S5 in the production procedure.
In such a condition, the slider substrate 64 is electrically charged due to irradiation with ions or electrons in a film deposition process for forming a silicon film and a carbon film by ECR-CVD and a dry etching process utilizing ion milling or the like. Since the slider substrate 64 made of Al2O3xe2x80x94TiC or the like is conductive, charges move from the slider substrate 64 into the bumps 66 in contact with the other end face 64d of another slider substrate 64, as shown in FIG. 24, whereby the head element 65 is electrostatically damaged.
Accordingly, an object of the present invention is to provide a magnetic head in which a head element is not electrostatically damaged even during a film deposition process using ECR-CVD and a dry etching process, and to provide a production method for the magnetic head.
In order to achieve the above object, according to a first aspect of the present invention, there is provided a magnetic head having a slider, wherein the slider includes a slider substrate, at least one of head element formed on one end face of the slider substrate, a protective film for covering the head element, and a plural bump electrically connected to the head element and having an exposed portion exposed from the protective film, and wherein the other end face of the slider substrate on the opposite side from the one end face with the head element is provided with an insulating-film.
In such a configuration of the magnetic head, the other end face of the charged slider substrate does not contact a bump formed of another slider substrate during the production procedure. Consequently, charges of the charged slider substrate will not move into the bump, and this can prevent electrostatic damage of the head element.
Preferably, the insulating film covers the entirety of the other end face of the slider substrate. This makes it possible to more reliably insulate the charged slider substrate from a bump of another slider substrate.
Preferably, the exposed portion of the bump is flush with or protrudes from the surface of the protective film. This makes it possible to select ball bonding or wire bonding in order to electrically connect the bump and a conductive pattern electrically connected to the outside.
According to a second aspect of the present invention, there is provided a magnetic head having a slider, wherein the slider includes a slider substrate, at least one of head element formed on one end face of the slider substrate, a protective film for covering the head element, and a plural bump electrically connected to the head element and having an exposed portion exposed from the protective film, and wherein the other end face of the slider substrate on the opposite side from the one end face with the head element has a projecting portion, and the distance from the surface of the protective film to the projecting portion formed on the other end face is longer than the distance from the exposed portion of the bump to the other end face.
In such a configuration of the magnetic head, the other end face of the charged slider substrate contacts the protective film formed on one end face of another slider substrate at its projecting portion, but does not contact the bump during the production procedure. Since charges of the charged slider substrate do not move into the bump, electrostatic damage of the head element can be prevented.
Preferably, the projecting portion is formed of an inclined face formed on the other end face. This makes it possible to more easily form the projecting portion by machining.
Preferably, the slider has a magnetic disk opposing surface opposing a magnetic disk, and the inclined portion has the top on the side of the magnetic disk opposing surface.
In such a configuration of the magnetic head, the projecting portion on the other end face of the slider substrate is in contact with the protective film formed on one end face of another slider substrate on the side of the magnetic disk opposing surface so as to close the side of the magnetic disk opposing surface. Therefore, foreign materials do not adhere to one end face and the other end face of the slider when working the magnetic disk opposing surface. This can prevent the magnetic disk from being damaged by foreign materials when the magnetic head is mounted in the hard magnetic disk device.
Preferably, the projecting portion is formed of a rib projecting from the other end face. This makes it possible to more easily form the projecting portion by machining.
Preferably, the slider has a magnetic disk opposing surface opposing a magnetic disk, and the rib is flush with the magnetic disk opposing surface.
In such a configuration of the magnetic head, the projecting portion on the other end face of the slider substrate is in contact with the protective film formed on one end face of another slider substrate on the side of the magnetic disk opposing surface so as to close the side of the magnetic disk opposing surface. Therefore, foreign materials do not adhere to one end face and the other end face of the slider when working the magnetic disk opposing surface. This can prevent the magnetic disk from being damaged by foreign materials when the magnetic head is mounted in the hard magnetic disk device.
Preferably, the exposed portion of the bump is flush with or protrudes from the surface of the protective film.
This makes it possible to select ball bonding or wire bonding in order to electrically connect the bump and a conductive pattern electrically connected to the outside.
According to a third aspect of the present invention, there is provided a magnetic head having a slider, wherein the slider includes a slider substrate, at least one of head element formed on one end face of the slider substrate, a protective film for covering the head element, and a plural bump electrically connected to the head element and having an exposed portion exposed from the protective film, and wherein the surface of the exposed portion of the bump is recessed from the surface of the protective film.
In such a configuration of the magnetic head, the other end face of the charged slider substrate contacts the protective film formed on one end face of another slider substrate, but does not contact the bump during the production procedure. Since charges of the charged slider substrate will not move into the bump, electrostatic damage of the head element can be prevented.
According to a fourth aspect of the present invention, there is provided a magnetic head production method including a head element forming step of forming, on a wafer, a plurality of head elements, a protective film for covering the head elements, and bumps electrically connected to the respective head elements, an insulating film forming step of forming an insulating film on the surface of the wafer opposite from the surface with the head elements, a slider bar forming step of cutting the wafer into a plurality of slider bars each having one side face with a plurality of head elements and the other side face with the insulating film, an arranging step of arranging the slider bar, formed in the slider bar forming step, in the same orientation so that a side face of one of adjoining slider bars having the insulating film is in contact with the bump or a side face of the protective film of the other slider bar, and a working step of forming magnetic disk opposing surfaces in the slider bars arranged in the arranging step by working so as to oppose a magnetic disk.
In such a magnetic head production method, since the insulating film is formed on the other side face of the slider bar, the bump formed on one side face of another slider bar does not contact the other side face of the charged slider bar in the working step. Therefore, charges of the charged slider bar will not move into the bump, and the head element is prevented from being electrostatically damaged.
According to a fifth aspect of the present invention, there is provided a magnetic head production method including a head element forming step of forming, on a wafer, a plurality of head elements, a protective film for covering the head elements, and bumps electrically connected to the respective head elements, a slider bar forming step of cutting the wafer with the head elements into a plurality of slider bars, a grinding step of grinding the other side faces of the slider bars on the opposite sides from the side faces with the head elements so as to form projecting portions, an arranging step of arranging the slider bars with the projecting portion in the same orientation so that the projecting portion of one of adjoining slider bars is in contact with the protective film for covering the head elements in the other slider bar and so that a space is formed between the exposed portion of the bump and the other side face, and a working step of forming magnetic disk opposing surfaces in the slider bars arranged in the arranging step by working so as to oppose a magnetic disk.
In such a magnetic head production method, since a space is formed between the other side face of the slider bar and the exposed portion of the bump formed on one side face of the adjoining slider bar, charges of the charged slider bar will not move into the bump, and the head element is prevented from being electrostatically damaged.
Preferably, in the arranging step, the projecting portion of one of the slider bars is in contact with a portion of the protective film for covering the head elements of the other slider bar excluding an exposed portion from which the bumps are exposed.
Preferably, in the grinding step, the projecting portion is formed of an inclined portion. This makes it possible to easily form the projecting portion.
Preferably, in the grinding step, the projecting portion is formed of a rib. This makes it possible to easily form the projecting portion.
According to a sixth aspect of the present invention, there is provided a magnetic head production method including a head element forming step of forming, on a wafer, a plurality of head elements, bumps electrically connected to the respective head elements, and a protective film for covering the head elements and the bumps, a photolithographic etching step of exposing exposed portions of the bumps from the protective film by forming a window in a position of the protective film formed in the head element forming step corresponding to the bumps, a slider bar forming step of cutting the wafer with the head elements into a plurality of slider bars, an arranging step of arranging the slider bars formed in the slider bar forming step in the same orientation so that the exposed portion of the bump of one of adjoining slider bars is in contact with the side face of the other slider bar with the head element formed thereon, and a working step of forming magnetic disk opposing surfaces in the slider bars arranged in the arranging step by working so as to oppose a magnetic disk.
In such a magnetic head production method, since a space is formed between the other side face of the slider bar and the exposed portion of the bump formed on one side face of the adjoining slider bar, charges of the charged slider bar will not move into the bump, and the head element is prevented from being electrostatically damaged.
Further objects, features, and advantages of the present invention will become apparent from the following description of the preferred embodiments with reference to the attached drawings.